/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.apache.dubbo.xds.istio;

import java.util.function.Supplier;

public interface XdsEnv {

    String getCluster();

    default String getStringProp(String key, String defaultVal) {
        String val = System.getenv(key);
        if (val == null) {
            val = System.getProperty(key);
        }
        if (val == null) {
            val = defaultVal;
        }
        return val;
    }

    default String getStringProp(String key, Supplier<String> defaultValSupplier) {
        String val = System.getenv(key);
        if (val == null) {
            val = System.getProperty(key);
        }
        if (val == null) {
            val = defaultValSupplier.get();
        }
        return val;
    }

    default Integer getIntProp(String key, String defaultVal) {
        String val = System.getenv(key);
        if (val == null) {
            val = System.getProperty(key);
        }
        if (val == null) {
            val = defaultVal;
        }
        return Integer.valueOf(val);
    }
}
